scholarly journals 165 SYNCHRONIZATION TREATMENT WITH NEW AND REUSED CIDR-B DEVICES: ESTRUS AND PREGNANCY RATES IN AN EMBRYO TRANSFER PROGRAM

2005 ◽  
Vol 17 (2) ◽  
pp. 233
Author(s):  
C.W. Solorzano ◽  
J.H. Mendoza ◽  
A. Villa-Godoy ◽  
C.S. Galina ◽  
S. Romo
Keyword(s):  
Embryo Transfer ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Estrus Synchronization ◽  
Transfer Program ◽  
Embryo Transfer Program ◽  
Group 3 ◽  
Group 2 ◽  
Rectal Palpation ◽  
Group 1

An earlier study demonstrated that in CIDRs used in adult cows on two previous occasions, there was still a sufficient amount of progesterone (P4) remaining that allowed estrus synchronization in heifers (Solorzano et al. 2004 Reprod. Fert. Dev. 16, 214). However, the diverse conditions existing in that study made a statistical comparison impossible. The objective of this study was to study the effect of new and used CIDRs, combined with estradiol benzoate (EB) and prostaglandin F2-α (PGF) treatments, on estrus synchronization rates (ESR) and pregnancy rates (PR) in an embryo transfer program in Brangus cows in a tropical climate. We used the same set of CIDRs in the same location in cows of the same breed, age, and body condition during three consecutive weeks. Cows were randomly allocated to one of three treatment groups. In Group 1, all cows (n = 44) were treated with a new 1.9-g CIDR (CIDR-B, InterAg, Hamilton, New Zealand), combined with 2 mg EB on Day 0. In Group 2, all cows (n = 43) were treated with a reused (first reuse) 1.9-g CIDR and 2 mg EB on Day 0. In Group 3, all cows (n = 42) received a reused (second reuse) 1.9-g CIDR and 2 mg EB on Day 0. CIDR devices were removed on Day 7 and all cows received PGF (0.25 μg cloprostenol) at that time. Estrus was expected to occur 24 h later. Seven days after estrus all cows showing heat were examined by rectal palpation, and those with a CL 15 mm in diameter or larger were selected to receive a frozen/thawed embryo (in 1.5 M ethylene glycol) by nonsurgical direct transfer. PR were determined by rectal palpation 60 days after estrus. In Group 1, a total of 90.9% of the cows displayed signs of estrus (40/44), and 42% of those that received a frozen embryo were pregnant (16/38). In Group 2, a total of 88.4% of the treated cows showed signs of estrus (38/43), and 37% of those recipients became pregnant (13/35). In Group 3, 88% of treated cows showed signs of estrus (37/42), and 36% of cows receiving an embryo were pregnant (13/36). ESR and PR were compared by χ2 and Fisher's tests, and no differences were found among the three groups studied. This confirms that, in 1.9-g CIDRs used on two previous and consecutive occasions, there is still a sufficient amount of P4 remaining that allows successful estrus synchronization and pregnancy rates in a third use.

scholarly journals Gestational losses after innovating with two embryos in a fixed-time embryo transfer program

2021 ◽  
Vol 14 (10) ◽  
Author(s):  
Carla Neves Barbosa ◽  
Felipe De Col ◽  
Juan Carlos Domínguez Fernández de Tejerina ◽  
Rodolfo Cassimiro de Araujo Berber
Keyword(s):  
Embryo Transfer ◽  
Birth Rate ◽  
Considerable Increase ◽  
Hormonal Treatment ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Corpora Lutea ◽  
Transfer Program ◽  
Embryo Transfer Program ◽  
Group 1

The aim of this study was to quantify the pregnancy rate after implantation of two embryos after FTET protocols, as well as to monitor pregnancy losses until parturition, evaluating, mainly, if this strategy results in more number of animals born. Therefore, 423 multiparous recipients were selected, standardized in terms of body score, who had high-quality corpora lutea. Animals were randomly divided into two groups according to one or two embryos transferred (1 embryo = Control, n = 237; 2 embryos = Group 1, n = 186). All recipients received the same hormonal treatment, which consisted of administering, on Day 0, 2 mL of estradiol benzoate (Gonadiol, ZOETIS) + 1.9 g multidose 1st use progesterone implant (CIDR, ZOETIS); on Day 8 the implants were removed + injected 0.4 mL of estradiol cypionate (E.C.P, ZOETIS) + 1.5 mL of eCG (Novormon, ZOETIS) + 1 mL of dinoprost tromethamine (Lutalyse, ZOETIS). The animals were evaluated by ultrasonography at 30 and 60 days after embryo transfer, to diagnose the success rate and embryo losses during this period. Furthermore, information was collected on births, length of gestation, number of twin births, number of childbirth assistance and the weight of the calves. The results showed that Group 1 had better success than the Control, with higher conception rates at 30 days (68.3% vs. 53.2%, P<0.001) and at 60 days (62.9% vs. 52.3%; P<0 .05). The number of animals born was also higher for Group 1 (53.3% vs. 43.3%, P<0.01). The percentage of twins born in Group 1 was 17.9%, and the animals had lower weight compared to the Control (34.29 + 7.36 vs 37.63 + 5.73, P<0.05). The length of pregnancy and the number of assistances were similar between groups. In conclusion, the strategy adopted in this experiment suggests a considerable increase in the calf birth rate, but losses during pregnancy and their mechanisms need to be elucidated.

219 COMPARISON OF ESTRUS - OVULATION SYNCHRONIZATION TREATMENTS USING HOLSTEIN HEIFERS AS EMBRYO TRANSFER RECIPIENTS

2007 ◽  
Vol 19 (1) ◽  
pp. 226
Author(s):  
H. Ushijima ◽  
N. Tatsuno ◽  
Y. Hara ◽  
T. Mori ◽  
H. Murata ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Final Diagnosis ◽  
Estradiol Benzoate ◽  
Visual Observation ◽  
Pregnancy Rates ◽  
Corpora Lutea ◽  
Estrus Synchronization ◽  
Gnrh Analog ◽  
Estrus Detection ◽  
Rectal Palpation

The Ovsynch system (Pursley et al. 1995 Theriogenology 44, 915–923) has been effectively employed as the synchronization method of recipients for embryo transfer (ET) (Nishisouzu et al. 2004 Reprod. Fertil. Dev. 16, 212–213). To establish the most effective Ovsynch system, we experimentally assessed 3 different protocols by comparing resultant estrus-synchronization rates of Holstein heifers and pregnancy rates of the recipients after ET. Holstein heifers averaging 14–15 months old and weighing over 330 kg were used in this study. They were randomly separated into the following 3 groups: (1) Select-synch (SS) group: an intramuscular (IM) injection of 50 �g GnRH analog was given to heifers at a random stage of the estrus cycle, followed 7 days later by 2 IM injections of 7.5 mg PG analog at an interval of 6 h; (2) Co-synch (CS) group: another IM injection of 50 �g GnRH was given to the SS group at 48 h after the first injection of PG; and (3) Heat-synch (HS) group: an IM injection of 0.75 mg estradiol benzoate was given to the SS group at 24 h after the first injection of PG. Estrus detection was evaluated twice daily by visual observation and use of a Heat Mount Detector. All heifers were additionally injected with 1500 IU hCG 5 days after estrus, to ensure favorable luteal function (Nishigai et al. 2001 J. Reprod. Dev. 47, 283–294). Rectal palpation was used to select acceptable recipients, i.e. those having functional corpora lutea (CL) e17 mm in diameter for 7 days after showing estrus (Nishisouzu et al. 2004 Reprod. Fertil. Dev. 16, 212–213). The size of CL e17 mm was determined by rectal palpation by skillful transferors. Fresh embryos collected from super-ovulated cattle 7 days after estrus were nonsurgically transferred only into acceptable recipients that had functional CL and were properly synchronized, 7–8 days after estrus. Final diagnosis of pregnancy was carried out 60 days after ET. Data were analyzed by the chi-square test. The HS group showed significantly higher (P &lt; 0.01) rates of estrus synchronization (87/89: 98%) at 24–72 h after PG injection, estrus detection (98%), and acceptable suitability as recipients with a functional CL (92%) compared to those of the SS (185/210: 88%, 87%, and 73%, respectively) and CS (68/81: 84%, 74%, and 69%, respectively) groups. The pregnancy rates of heifers that received an embryo were not significantly different among HS, SS, and CS groups (45/82: 55%, 78/153: 51%, and 25/56: 45%, respectively). However, because the yield rate of acceptable recipients in the HS group was higher than in the other groups, the final pregnancy rates (no. pregnant/no. synchronization treatment) of the HS group (50%) was significantly higher than those of the SS and CS groups (37%; P &lt; 0.05, and 31%; P &lt; 0.01, respectively). Taken together, these findings demonstrate that the HS protocol is effective for estrus–ovulation synchronization of Holstein heifers, thus improving the productivity of ET by increasing the yield rates of heifers with a functional CL which leads to acceptable pregnancy results.

192 THE USE OF FIXED-TIME TECHNIQUES AND eCG TO SYNCHRONIZE RECIPIENTS for FROZEN - THAWED BOVINE IVF EMBRYOS

2006 ◽  
Vol 18 (2) ◽  
pp. 204 ◽  
Author(s):  
R. Remillard ◽  
M. Martínez ◽  
G. Bó ◽  
R. Mapletoft
Keyword(s):  
Embryo Transfer ◽  
Animal Health ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Group 4 ◽  
Estrus Detection ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Group 1

Two experiments were designed to investigate the use of eCG in a fixed-time embryo transfer (FTET) protocol for Chinese Yellow crossbred recipients receiving in vitro-produced (IVP) bovine embryos. In Experiment 1, cows were observed for spontaneous estrus (Group 1) or following 500 �g cloprostenol (PGF; Schering-Plough Animal Health, Montreal, Quebec, Canada; Group 2) with nonsurgical embryo transfer 7.5 or 8.0 days later. Cows in Groups 3, 4, and 5 were treated with a CIDR insert (Bioniche Animal Health, Beijing, China), 2 mg estradiol benzoate (EB), and 50 mg progesterone (Sigma-Aldrich, Canada) i.m. on Day 0, PGF on Day 5, CIDR removal on Day 7, and 1 mg EB i.m. 24 h later with nonsurgical transfer of Holstein IVP embryos 8.5 days later, without estrus detection. In addition, cows in Group 3 received no further treatment, whereas cows in Group 4 received 400 IU eCG i.m. (Pregnecol; Bioniche) on Day 5, and cows in Group 5 received eCG on Day 7. Holstein embryos were produced utilizing slaughterhouse ovaries and standard IVF procedures. Expanded blastocysts of quality grade 1 (IETS) were cryopreserved in 10% ethylene glycol and 20% fetal bovine serum using standard procedures. Straws were thawed in a 30�C water bath, and embryos were expelled directly into holding medium and evaluated prior to nonsurgical transfer (NT) ipsilateral to the corpus luteum (CL). Pregnancy was diagnosed ultrasonically 30 d later. Although pregnancy rates, based on numbers of recipients synchronized, numerically favored the administration of eCG on Day 5, there were no significant differences (P = 0.40) among groups (Group 1: 15.4%, n = 52; Group 2: 20.0%, n = 50; Group 3: 19.2%, n = 99; Group 4: 28.1%, n = 96; Group 5: 21.3%, n = 75). In Experiment 2, Chinese Yellow crossbred cattle were synchronized with a CIDR insert plus estradiol and progesterone on Day 0, PGF on Day 5, CIDR removal on Day 7 and estradiol on Day 8, and were randomly assigned to received no further treatment (Group 1; n = 400) or an injection of 400 IU eCG on Day 5 (Group 2; n = 391). Recipients with a detectable CL received a frozen-thawed IVP Holstein embryo by NT 8.5 days after the second injection of estradiol without estrus detection, as in the first experiment. Pregnancy diagnosis was done ultrasonically 30 days later. Although CL size, cow age, and embryo quality, prior to transfer, were recorded, no effects on pregnancy rates were demonstrated (P = 0.30). Pregnancy rates, based on recipients receiving embryos, did not differ (P = 0.5) between groups (Group 1: 21.4%, n = 154; Group 2: 24.5%, n = 290). Overall pregnancy rates (based on the total number of recipients synchronized) were significantly higher (P < 0.001) in Group 2 (eCG; 18.2%) than in Group 1 (no eCG; 8.3%), because of the significantly higher (P < 0.03) percentage of recipients used following treatment with eCG (74.2% vs. 38.5%). Results indicate that the administration of eCG on Day 5 of an 8-d synchronization protocol for FTET of frozen-thawed bovine IVP embryos will improve pregnancy rates in beef recipients, especially those of marginal quality.

176 PREGNANCY AND PREGNANCY LOSS RATES OF ACYCLIC RECIPIENT MARES TREATED WITH TWO DIFFERENT LONG-ACTING PROGESTERONE CONCENTRATIONS

2010 ◽  
Vol 22 (1) ◽  
pp. 246 ◽  
Author(s):  
G. M. Greco ◽  
J. A. Dell'aqua Jr ◽  
M. A. Alvarenga
Keyword(s):  
Embryo Transfer ◽  
Pregnancy Loss ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Chi Square ◽  
Chi Square Test ◽  
Group 2 ◽  
Long Acting ◽  
Group 1 ◽  
Loss Rates

Long-acting progesterone compounds containing concentrations of 150 mg mL-1 (P4LA150) have been routinely used in Brazil, especially at the beginning and end of the breeding season when the percentage of recipient mares showing normal estrous cycles is low compared to donors (Greco GM et al. 2008 Proceedings 7th International Symposium on Equine Embryo Transfer, 59-60). However, recipients treated with P4LA150 must receive weekly administrations until pregnancies achieve 100 days. The present study aimed to evaluate pregnancy and pregnancy loss rates from acyclic mares treated at 7-day intervals with P4LA150 and 14-day intervals with a long-acting progesterone formulation containing 300 mg mL-1 (P4LA300). Acyclic Campolina breed mares (n = 80) ranging from 4 to 13 years old showing considerable endometrial edema 2 days after estradiol benzoate injection (5 mg, i.m.) were split in 2 groups. Group 1 mares (n = 40) received 10 mL of P4LA150 (1500 mg) i.m. every 7 days, whereas Group 2 mares (n = 40) were treated with 10 mL of P4LA300 (3000 mg) i.m. every 14 days. Steroid hormone formulations were produced in our research laboratory, at São Paulo State University, Botucatu, Brazil. Embryos 7 to 8 days of age were transferred into the uteri of recipients between 4 and 7 days after the first progesterone administration. Following a positive pregnancy diagnosis at 14 to 15 days, mares were examined at Days 50 and 100, when progesterone treatment was discontinued. These evaluations were conducted in order to determine pregnancy loss rates during both periods. Results were analyzed through the chi-square test and significance was set at P < 0.05. Pregnancy rates and pregnancy loss rates at Day 50 from mares treated with P4LA150 (Group 1) and P4LA300 (Group 2) did not differ. Pregnancy rates were 60.0% (24/40) and 75.0% (30/40) at Day 50 for mares treated with P4LA150 (Group 1) and P4LA300 (Group 2), respectively (P > 0.10). Pregnancy loss rates at Day 50 were 8.3% (2/24) and 10.0% (3/30) for mares treated with P4LA150 and P4LA300, respectively (P > 0.10). Pregnancy losses were not identified at Day 100. Based on the results from the present study, we concluded that acyclic recipient mares treated with P4LA150 or P4LA300 are able to obtain satisfactory pregnancy rates with low pregnancy losses. Moreover, the use of 3000 mg of long-acting progesterone every 14 days reduces overall progesterone administrations, minimizes stress in horse handling, and makes the choice for acyclic recipient mares more appealing in commercial embryo transfer programs. Authors would like to thank FAPESP for financial support.

74 Body condition of donor animal and recipients affects the outcome of embryo transfer program in dromedary camel (Camelus dromedarius)

2021 ◽  
Vol 33 (2) ◽  
pp. 144
Author(s):  
B. S. Vettical ◽  
N. A. Wani
Keyword(s):  
Embryo Transfer ◽  
Body Condition ◽  
Intramuscular Injection ◽  
The Body ◽  
Positive Energy ◽  
Transfer Program ◽  
Significant Difference ◽  
Embryo Transfer Program ◽  
Group 3 ◽  
Group 1

The present study was conducted in dromedary camels to evaluate the effect of the body condition of donor animals on the outcome of superstimulation and embryo collection in experiment 1 and the establishment of pregnancies in the recipients in experiment 2. The animals were physically evaluated for their body condition and scored on a scale of 0 to 5 (0 being very thin and weak, while 5 being very fat). They were divided into three groups based on their body condition score (BCS). Animals with a score of 1–2, &gt;2–3, and &gt;3–4 were divided into groups 1, 2, and 3, respectively. Animals with a score of &lt;1 and &gt;4 were considered either too weak or too fat and were not included in the study. In Experiment 1, 32 donors in 3 groups were superstimulated with a combination of 2500IU of equine chorionic gonadotrophin (eCG, Folligon; Intervet), given as a single intramuscular injection on Day 1 of the treatment protocol, and 400mg of pFSH (Folltropin; Bioniche) injected twice daily in declining doses of 2×80mg, 2×60mg, 2×40mg, and 2×20mg over 4 days, also beginning on Day 1. The ovaries of all the donor camels were scanned on Day 4 after the start of treatment, and thereafter at intervals of one or two days until the majority of follicles had grown to between 1.3 and 1.8cm in diameter before mating with a fertile male. Each donor received an intramuscular injection of 20µg of gonadotrophin-releasing hormone (Receptal, Intervet) immediately after mating, and embryos were collected by non-surgical method on Day 7 after ovulation. In Experiment 2, 141 recipients divided in 3 groups, as described above, were synchronized with donors and received an embryo each in their left uterine horn. The pregnancy confirmation was done by an ultrasound examination on Day 50 after transfer. Data were analysed by ANOVA with Fisher protected least significant difference test (Minitab statistical software, Minitab Ltd.). In experiment 1, the mean±s.e.m. number of follicles (13.9±1.3; 12.7±2.9; 15.0±1.7), and the percent mean±s.e.m. of embryos collected (41.5±7.7; 57.0±12.3; 60.4±7.8) were not different among groups 1, 2 and 3, respectively. However, the percent mean±s.e.m. of transferrable embryos obtained were higher (P&lt;0.05) in group 3 (77.7±4.8) compared with group 1 (57.5±10.1). Similarly, in experiment 2, the percent mean±s.e.m. of pregnancies achieved in group 3 (68.9±6.4) was similar to that of group 2 (57.9±14) but higher (P&lt;0.05) than that of group 1 (50.5±10.0). In conclusion, to the best of our knowledge, this is the first study showing a direct correlation between the BCS and outcome of embryo transfer program in camels. Donors with a good BCS produced more transferrable embryos, and conception rates were higher in recipients having a better BCS. This clearly shows that not only is the selection of recipients critical in the embryo transfer program, but donors with a positive energy balance yield better transferrable embryos. Priming of donors before the start of the breeding season could help to improve the outcome of this technology in camels.

207 INFLUENCE OF THE INTERVAL BETWEEN THAWING TO TRANSFER ON PREGNANCY RATES OF FROZEN - THAWED DIRECT-TRANSFER EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 220
Author(s):  
G. A. Bo ◽  
L. C. Peres ◽  
D. Pincinato ◽  
M. de la Rey ◽  
R. Tribulo
Keyword(s):  
Bos Taurus ◽  
Body Condition Score ◽  
Bos Indicus ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Direct Transfer ◽  
Condition Score ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

An experiment was designed to evaluate the effect of the interval between thawing to deposition of the embryo into the uterine horn on pregnancy rates of in vivo-produced frozen–thawed embryos in 1.5 M ethylene glycol (direct transfer). Data were collected from 1122 embryo transfers performed in the same farm (Estancia El Mangrullo, Lavalle, Santiago del Estero, Argentina) during the spring and summer of 2004/05 and 2005/06 (6 replicates, ambient temperature between 20 and 40�C). Recipients used in all replicates were non-lactating, cycling, multiparous Bos taurus � Bos indicus crossbred cows with body condition score between 3 and 4 (1 to 5 scale) that were synchronized using fixed-time embryo transfer protocols. Briefly, the synchronization treatments consisted of the insertion of a Crestar ear implant (Intervet, Sao Paulo, Brazil) or a progesterone-releasing device (DIB; Syntex SA, Buenos Aires, Argentina), plus 2 mg of estradiol benzoate (EB; Syntex) intramuscularly (IM) on Day 0, and 400 IU of eCG (Folligon 5000; Intervet, or Novormon 5000; Syntex) IM plus 150 �g d-cloprostenol IM (Preloban; Intervet, or Ciclase; Syntex) on Day 5. Progestin devices were removed on Day 8 and all cows received 1 mg of EB IM on Day 9. All cows were examined by ultrasonography on Day 16 and those with a luteal area &gt;76 mm2 (by calculating the area of the CL minus the area of the cavity) received, on Day 17, frozen–thawed embryos by nonsurgical transfer. All embryos were Grade 1, and all were frozen in 1.5 M ethylene glycol at the Embryo Plus Laboratory (Brits, South Africa). After being stored in liquid nitrogen, the embryos were plunged directly (no air thawing) in a 30�C water bath for 30 s, and then transferred to the recipient cows by either one of two technicians. Based on the interval between thawing and transfer, the transfers were classified as being in one of 3 groups: Group 1: &lt;3 min; Group 2: 3 to 6 min; and Group 3: 6 to 16 min. The main reason for delayed transfers beyond 6 min was the replacement of one recipient for another because of difficulty in threading the cervix (1% of the total transfers) or a recipient falling down into the chute or with very bad disposition and behavior. Pregnancy was determined by ultrasonography 28 to 35 days after fixed-time embryo transfer, and data were analyzed by logistic regression. There were no effects of replicate, technician, CL area, recipient body condition score, embryo stage, and time from thawing to transfer on pregnancy rates. Pregnancy rates in the 3 thawing to transfer intervals were: Group 1: 215/385, 55.8%; Group 2: 372/655, 56.8%; Group 3: 42/82, 51.2%; P &gt; 0.6. These results may be interpreted to suggest that there is no significant effect of time from thawing to transfer (up to 16 min) in direct transfer embryos using Bos taurus � Bos indicus recipients transferred at a fixed time.

151 EFFECT OF RECIPIENT CATEGORY ON PREGNANCY RATES ON A BOVINE EMBRYO TRANSFER PROGRAM IN PATAGONIA, ARGENTINA

2008 ◽  
Vol 20 (1) ◽  
pp. 155
Author(s):  
J. Villarreal ◽  
A. Garcia Guerra ◽  
G. M. Brogliatti
Keyword(s):  
Embryo Transfer ◽  
Pregnancy Rates ◽  
Point Of View ◽  
Bovine Embryo ◽  
Transfer Program ◽  
Chi Square ◽  
Lactating Cows ◽  
Significant Difference ◽  
Embryo Transfer Program ◽  
Condition Score

The fertility of the recipient is one of the more important factors conditioning the success of an embryo transfer (ET) program. Selection and management of recipients is a very important contributing factor to achieve high pregnancy rates (Stroud and Hasler 2006 Theriogenology 65, 65–76). From a reproductive point of view, a good recipient is a cow capable of receiving an embryo and taking it to term (Palma et al. 2001 Biotecnologia de la reproduccion, INTA). In beef and dairy cattle, recipients are categorized according to number of births, age, and condition score (Stroud and Hasler 2006). A retrospective analysis was done to confirm a relationship between recipient category, based on their physiologic and reproductive stage, and pregnancy rates. The analysis was done during January and February (2006–2007) based on data recovered from an embryo transfer program done in Chubut province (Patagonia) for the project ‘Polo Genetico Angus’ (Angus Association – Chubut government agreement). Two hundred and seven morulas and/or blastocysts, quality 1 or 2 frozen in 1.5 m ethylene glycol (IETS manual), were transferred randomly in 10 different farms. Embryos were thawed for 10 s at room temperature and 30 s in a water bath at 35°C and transferred by one single technician. Angus, Hereford, or its breeds were used as recipients. A reproductive exam was performed before embryo transfer and, based on it, recipients were classified into 4 categories: heifer (3–4 years old), lactating cow, weaned cow, and dry old cow (Table 1). The synchronization protocol used for recipients consisted of a single administration of D-cloprostenol and heat detection twice a day for 5 days. Data were analyzed by Cochran-Mantel-Haenszel test (chi-square). Results are shown in Table 1. There is a significant difference (P ≤ 0.05) in pregnancy rates among categories. Recipients with higher pregnancy rates were lactating cows and weaned cows 61.6% and 56.9%, respectively, compared to heifers, 45.3%; a lower pregnancy rate was founded in the dry old cows group. Dry cows were animals that failed to get pregnant during the last season. Heifers also were animals that failed the artificial insemination program. In both groups, the reduced fertility may explain their lower pregnancy rates. In conclusion, selection toward fertility of recipients is a very important factor to take into account to design a successful embryo transfer program. Table 1. Pregnancy rates for recipient categories in an ET program in Chubut (Patagonia), Argentina This research was supported by Centro Genetico Bovino Eolia.

scholarly journals Effect of the Flunixin Meglumine on Pregnancy Rates in an Equine Embryo Transfer Program

2018 ◽  
Vol 62 ◽  
pp. 40-43 ◽  
Author(s):  
Carolina Tiemi Cardoso Okada ◽  
Lorenzo Garrido Segabinazzi ◽  
André Maciel Crespilho ◽  
José Antônio Dell'Aqua ◽  
Marco Antonio Alvarenga
Keyword(s):  
Embryo Transfer ◽  
Pregnancy Rates ◽  
Transfer Program ◽  
Flunixin Meglumine ◽  
Embryo Transfer Program

Interactions of oxytocin, potassium, and calcium in the rat uterus

1961 ◽  
Vol 201 (5) ◽  
pp. 931-934 ◽  
Author(s):  
Elwin Berger ◽  
Jean M. Marshall
Keyword(s):  
Surrounding Medium ◽  
Estradiol Benzoate ◽  
Stimulatory Action ◽  
White Rats ◽  
Tenfold Increase ◽  
Group 3 ◽  
Group 2 ◽  
K Concentration ◽  
Group 1 ◽  
External K

Ovariectomized white rats were treated as follows: group 1, 70 µg estradiol benzoate every other day for 9 days; group 2, 3.1 mg aqueous progesterone daily for 4 days then 6.2 mg daily for 5 days; group 3, untreated controls. Spontaneous muscle contractions were recorded isometrically from isolated uterine horns. Uteri from the estrogen-treated animals were the most sensitive to the stimulatory action of oxytocin (5 mu/ml). The action of oxytocin remained essentially unchanged in the presence of a tenfold increase in external K concentration in both the estrogen-treated and progesterone-treated muscles. A reduction in the Ca concentration of the surrounding medium markedly reduced the effectiveness of oxytocin. This decline in oxytocin potency was most pronounced in the estrogen-treated uteri.

Sign in / Sign up

Export Citation Format

Share Document